System and method for regulating the heat management of a vehicle

ABSTRACT

The invention relates to a system to regulate the heat balance of a vehicle, with a heat cycle that dissipates engine heat, which features a cooling circuit ( 38 ) and a heating circuit ( 36 ), through which circuits a coolant can flow, and with at least one component ( 20 ) of the vehicle producing waste heat, wherein a system is provided with which the waste heat of at least one component of the vehicle can be transferred to the heat cycle.

The present invention relates to a system to regulate the heat balanceof a vehicle, with a heat cycle that dissipates engine heat, whichfeatures a cooling circuit and a heating circuit, through which circuitsa coolant can flow, and at least one component of the vehicle producingwaste heat. In addition, the invention relates to a method to regulatethe heat balance of a motor vehicle.

PRIOR ART

A combustion engine for a motor vehicle has a heat cycle, which can besubdivided into a cooling circuit and a heating circuit. The coolingcircuit serves to dissipate engine heat into the ambient air and to coolthe engine, wherein engine heat is first delivered to the coolingcircuit to a therein circulating coolant, which is conveyed via acoolant pump to a cooling element of the cooling circuit. In this way,absorbed heat is released to the air flowing through the cooler. Theheating circuit of the heat cycle through which the same coolant flowsis used to heat the passenger compartment of the vehicle. The heatingcircuit features a heater heat exchanger with which the heat of thecoolant is released to the ambient air flowing in the vehicle'spassenger compartment. It is desirable when operating a combustionengine to reach high operating temperatures of the engine as quickly aspossible in order to optimize the combustion that is occurring in theengine. As a result, emissions of pollutants can be reduced and exhaustgas limit values can be complied with. In this regard, in order to heatup the engine more quickly during the warm-up phase, a known method iscircumventing the cooling element of the cooling circuit with athermostat-regulated bypass line so that the coolant does not circulatethrough the cooling element until the thermostat opens based upon theengine reaching an operating temperature. In addition, it isparticularly desirable in the case of cold outside temperatures to beable to use the waste heat of the engine as quickly as possible to warmup the engine. Since the heating capacity is low due to the reduced heatemission of the engine in its warm-up phase, integrating fuel-operatedor electrically operated auxiliary heaters into the heat cycle, withwhich the air flowing in the vehicle's passenger compartment and/orcoolant is heated, is known from the prior art.

ADVANTAGES OF THE INVENTION

The system in accordance with the invention to regulate the heat balanceof a vehicle builds on the generic prior art in that a system isprovided with which the waste heat of at least one component of thevehicle can be transferred to the heat cycle.

The system to transfer the waste heat of a component of the vehicle canbe a system with a housing, which makes it possible for coolant to flowaround the parts of the component that are giving off waste heat. Thewaste heat of the component of the vehicle can be transferred via theheating circuit or the cooling circuit to the heat cycle. In the case ofthe system in accordance with the invention, a heat source of acomponent of the vehicle is incorporated into the heat cycle of theengine, whereby the coolant of the heat cycle can heat up more quickly.This produces both an accelerated heating up of the engine, whichresults in a reduction of fuel consumption and the emission ofpollutants, as well as increased comfort for the vehicle passengerssince the passenger compartment of the vehicle can be heated up morequickly due to the heat supply from the components of the vehicle anddue to the quicker heating of the coolant. The latter also produces anincreased standard of safety since quicker de-icing of the vehiclewindow is possible in the case of cold outside temperatures. In anycase, realized in the system in accordance with the invention is thatthe heating capacity of a planned heater in the heat cycle of the enginedoes not depend only on the operating state of the engine heat cycle toheat up the passenger compartment of the vehicle, rather the opposite istrue that said heating capacity contributes to the heating of thecooling circuit of the engine. In this regard, the auxiliary heaterknown from the prior art or an independent vehicle heater for theheating circuit of the heat cycle can be used in such a way that thecoolant of the heat cycle is also heated in addition to heating the airfed into the passenger compartment of the vehicle. Thus, a well-balancedheat balance is realized in the motor vehicle particularly during thewarm-up phase of the engine.

It must be emphasized in this connection that several components of thevehicle can be provided whose respective waste heat can be transferredto the heat cycle of the engine. Furthermore, additional systems thatare known from the prior art and do not need to be discussed areprovided to realize the heat transfer of a component of the vehicle.Thus, an additional coolant pump, for example, can be provided tocirculate the coolant through the system planned in accordance with theinvention. Furthermore, it must be emphasized that in general a transferof the waste heat of a component can be prevented by a valve or blockingdevice if for example the engine has reached an adequate or specificoperating temperature.

According to Claim 2, heat that is made available via the airconditioner cycle process is transferred via a refrigerant of the airconditioner through a coupling heat transfer medium to the coolant ofthe heat cycle of the engine. The heat transfer medium of the airconditioner can then be coupled in the process to the cooling circuit orthe heating circuit of the heat cycle. Depending upon the type of designand control or regulation of the heat transfer medium of the aircondition, additional valves such as mixing valves and control valvescan be provided. In this regard, it is also possible to reverse the heatcycle of the air conditioner via planned air conditioner components inorder to be able to use the air conditioner as a heat pump particularlyin the case of low ambient temperatures, whereby the heat emitted by theheat pump is transferred in turn to the heat cycle of the engine inorder to the heat the coolant that is circulating in it. As a result,this cycle can also be executed when the engine is at a standstill as anindependent vehicle heater process. Due to the heating of the coolant,the temperature of the engine can be increased as a result beforestarting the combustion engine by the heated coolant being circulatedthrough the engine. The result of this is that the engine heats up morequickly, thereby reducing emissions and fuel consumption from the momentthe engine starts onward.

According to an advantageous embodiment, it is provided according toClaim 3 that the heat transfer medium of the air conditioner can becircumvented via a bypass line. As a result, temperature regulation ispossible at the heat transfer medium, because the heat yield in the heattransfer medium can be varied via the returned heat quantity of themedium flowing though the heat transfer medium. The bypass line ispreferably attached via at least one suitable valve, which can be usedto completely or partially open or close it so that the rate of flow isadjustable.

Moreover, it is possible in accordance with an advantageous embodimentaccording to claim 4 to use the auxiliary heating device, which isprovided to heat the ambient air flowing in the passenger compartment ofthe vehicle, to also heat the coolant.

The method in accordance with the invention to regulate the heat balanceof a motor vehicle builds on the generic prior art in that the wasteheat is transferred to the heat cycle by at least one component of thevehicle. The explanations with respect to the aforementioned system inaccordance with the invention to regulate the heat balance of a motorvehicle should be read in the same or similar manner with respect to themethod in accordance with the invention and the advantages referred toare transferable to it, whereby a repetitious discussion thereof isdispensed with in order to avoid redundancy.

The essential basic idea of the invention is to incorporate those typesof components of the vehicle into the heat cycle of the engine, whosewaste heat can be used to heat the coolant in order to contribute to thepassenger compartment and the engine heating up more quickly.

DRAWING

The invention will now be explained by way of example on the basis ofpreferred exemplary embodiments making reference to the encloseddrawing.

The drawing shows:

FIG. 1 A schematic representation of a heat cycle of a motor vehicle, inwhich a heat transfer medium of an air conditioner of a vehicle isincorporated at various positions, with which waste heat can betransferred to the heat cycle.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 shows a heat cycle of a combustion engine 10 of a motor vehicle.The heat cycle is used to regulate the operating temperature in anengine block 11 and a cylinder head 12 of the engine 10 as well as toregulate the temperature of the vehicle's passenger compartment. Theheat cycle includes a cooling circuit 38, which leads from an engineblock 11 of the engine 10 via a coolant or main water pump 22 and acooling element 26 to the cylinder block 12 (there is a reverse pumpdirection in the cooling operation). Because of the main water pump 22,it is possible to circulate a coolant in 5 order release the heattransferred from the engine 10 to the coolant through the coolingelement 26 to the ambient air. Flow-through of the cooling element withair that is required in the case of a standstill of the vehicle is alsoprovided for via a cooling element fan 28. A bypass line to circumventthe cooling element is attached between valves 24, 32, which can be usedto separate the cooling element branch in the case of cold enginetemperatures in order to store the waste heat of the engine in coolantand increase the operating temperature of the engine with it as quicklyas possible. The heating circuit 36 of the heat cycle leads from thecylinder head 12 of the engine 10 via an optional exhaust gasrecirculation cooling element 14 to a heater heat exchanger 16 and viathe main water pump 22 back to the engine 10. Because of the connectionof the heating circuit 36 to the cooling circuit 38, only a single mainwater pump 22 is required. However, as shown in FIG. 1 an additionalwater pump 18 can be provided for the heating circuit 36 as analternative. Furthermore, an oil heat exchanger 34 can be incorporatedinto the heat cycle of the engine 10. It is provided in accordance withthe invention that at least one component of the vehicle be integratedinto the heat cycle so that the waste heat from the component can beused to heat the coolant in the heat cycle.

According to FIG. 1, a coupling heat transfer medium 20 of an airconditioner of the vehicle is integrated into the heat cycle of theengine 10 in an exemplary manner and is used to accomplish a heattransfer of the waste heat generated by the air conditioner to the heatcycle of the engine. In order to heat up the passenger compartment in anoptimal way, with a closed valve 24 and an open valve 38, the-coolantcan first be pumped only through the additional water pump 18 directlyinto the cylinder head 12 and then into the heat cycle 36. As shown inFIG. 1, the heat transfer medium 20 can be integrated at various pointsin the heat cycle, i.e., both in the cooling circuit 38 as well as inthe heating circuit 36 of the heat cycle. In this case, Position 1through Position 6 indicate possible integration positions for the heattransfer medium 20. According to Position 1, the heat transfer medium 20is integrated into the heating circuit 36 of the engine 10. A bypassline 44 around the heat transfer medium 20 is provided to regulate heatbalance of the heat transfer medium 20. In this connection, theadditional water pump 18 can also be provided in the flow directionbehind the heat transfer medium 20 in accordance with Position 6. Basedon this arrangement, heat from the air conditioner that is transferredthrough the heat transfer medium 20 to the heating circuit 36 is used toheat the engine first. Furthermore, it is possible to provide a bridgeline 40 in the heating circuit 36, with which coolant can be directedvia a heat transfer medium mixing valve (not shown) arranged in the flowdirection behind the heat transfer medium 20 from the heat transfermedium 20 to the entrance of the exhaust gas recirculation coolingelement 14. Thus, for example the heat transfer medium 20 can also beprovided with a bypass line (not shown) in the bridge line 40.

The heat transfer medium mixing valve can be a proportional valve withtwo branches that can be throttled, for example. In addition, a shortcircuit line 42 can lead from the main water pump 22 to the entrance tothe heat transfer medium 20, for example via a mixing valve. If a shortcircuit line 42 is provided, temperature regulation at the heat transfermedium is possible, whereby the bypass around the heat transfer medium20 is no longer required. This short circuit line 42 can also beprovided for the bridge line 40. In the case of integrating the heattransfer medium 20 into the bypass line of the cooling circuit 38between the valves 24 and 32 in accordance with Position 2, there is noflow through the heat transfer medium 20 if the valve to the coolingelement 26 is opened. However, it can then be assumed that the coolantis warm then and no auxiliary heating is desired. The heat can also beused for engine warm-up without the flow having to pass through theheating branch. In contrast, when the heat transfer medium 20 isintegrated in accordance with Position 3, there is always flow throughthe heat transfer medium 20. In accordance with an integration of theheat transfer medium 20 at Position 4, the introduced heat is releasedwith priority via the heater heat transfer medium 16 into the passengercompartment of the vehicle. The coolant entrance temperatures in theheat transfer medium 20 are higher in general at this position than atPosition 1 through Position 3 and Position 6, whereby the temperaturedifference driving the heat transfer is smaller. In the case ofintegration of the heat transfer medium 20 in accordance with Position5, the coolant entrance temperature in the heat transfer medium 20 isgreater as compared with Position 1 through Position 4 and Position 6.This position makes possible the most direct possible coupling of theheat via the heater heat transfer medium into the passenger compartmentof the vehicle.

Reference is again made to the fact that the flow directions illustratedby arrows in FIG. 1 are applicable for a switched-on supplementarycoolant pump 18 and a closed valve 24.

The foregoing description of the exemplary embodiments according to theinvention is for illustrative purposes only and not for the purposes oflimiting the invention. Within the framework of the invention, variouschanges and modifications are possible without leaving the scope of theinvention as well as their equivalents.

For example, the simple heater heat exchanger 16 shown in FIG. 1 can bereplaced by a heater heat exchanger that is divided into two parts. Thiscan also have a bypass. It is also possible to provide the heat transfermedium mixing valve as a simply designed valve in certain cases. Inaddition, it is possible to make parts of heat cycle shown in the figureoptional or to arrange these at another location. As a result, theinvention can also be realized on a heat cycle without an exhaust gasrecirculation cooling element 14, or the compensation vessel 30 or theoil heat exchanger 34 is connected at another location of the heatcycle. Moreover, the mixing valve for the heat transfer medium 20 can bedesigned in such a way that the connected branch can be closedcompletely and one of the other branches is throttled. In addition, itis possible to drive and regulate or turn on or shut down the main waterpump 22 and/or the additional water pump 18 electrically or by amechanical output of the combustion engine.

1. System to regulate the heat balance of a vehicle, with a heat cyclethat dissipates engine heat, which features a cooling circuit (38) and aheating circuit (36), through which circuits a coolant can flow, and atleast one component (20) of the vehicle producing waste heat,characterized in that a system is provided with which the waste heat ofat least one component (20) of the vehicle can be transferred to theheat cycle.
 2. System according to claim 1, characterized in that theentire engine is not integrated into the heat cycle, but predominantlythe areas in which waste heat is produced, for example the combustionchambers and/or the Y-cooling, in particular in order to achieve a hightemperature level more quickly during warm-up.
 3. System according toclaim 1, characterized in that the component producing the waste heat isa heat transfer medium (20) of an air conditioner, whose waste heat canbe transferred to the heat cycle.
 4. System according to claim 1,characterized in that a bypass line (44) is provided for the heattransfer medium (20).
 5. System according to claim 1, characterized inthat an auxiliary heating device is provided in the heating circuit (36)of the heat cycle, whose waste heat can be transferred to the heatcycle.
 6. Method to regulate the heat balance of a vehicle, with a heatcycle that dissipates engine heat, which features a cooling circuit (38)and a heating circuit (36), and at least one component (20) of thevehicle producing waste, characterized in that waste heat of the atleast one component (20) of the vehicle is transferred to the heatcycle.
 7. Method according to claim 6, characterized in that asupplementary coolant pump is provided, which in at least one operatingmode pumps directly into a cylinder head, particularly in the case of aninactive main coolant pump.
 8. System according to claim 2,characterized in that the component producing the waste heat is a heattransfer medium (20) of an air conditioner, whose waste heat can betransferred to the heat cycle.
 9. System according to claim 2,characterized in that a bypass line (44) is provided for the heattransfer medium (20).
 10. System according to claim 3, characterized inthat a bypass line (44) is provided for the heat transfer medium (20).11. System according to claim 2, characterized in that an auxiliaryheating device is provided in the heating circuit (36) of the heatcycle, whose waste heat can be transferred to the heat cycle.
 12. Systemaccording to claim 3, characterized in that an auxiliary heating deviceis provided in the heating circuit (36) of the heat cycle, whose wasteheat can be transferred to the heat cycle.
 13. System according to claim4, characterized in that an auxiliary heating device is provided in theheating circuit (36) of the heat cycle, whose waste heat can betransferred to the heat cycle.
 14. Method according to claim 6,characterized in that the entire engine is not integrated into the heatcycle, but predominantly the areas in which waste heat is produced, forexample the combustion chambers and/or the Y-cooling, in particular inorder to achieve a high temperature level more quickly during warm-up.15. Method according to claim 6, characterized in that the componentproducing the waste heat is a heat transfer medium (20) of an airconditioner, whose waste heat can be transferred to the heat cycle. 16.Method according to claim 6, characterized in that a bypass line (44) isprovided for the heat transfer medium (20).
 17. Method according toclaim 6, characterized in that an auxiliary heating device is providedin the heating circuit (36) of the heat cycle, whose waste heat can betransferred to the heat cycle.